The transmission spectrum and demodulation curve of the fiber ring resonator were simulated.As can be seen,the lowest value of transmission spectrum was corresponding to the modulation resonance point,the linear zone of demodulation curve was the dynamic range of gyroscope,the midpoint of the linear region was corresponds to the resonance point and it could be used as the maximum of scale factor.In order to achieve the high accuracy and steady frequency locked of the resonance point,resonant gyroscope angular velocity measurement scheme was designed,which used proportional integral circuit to lock the resonant frequency and sine wave to scan the piezoelectric transducer of narrow linewidth laser (linewidth is less than 1 kHz),so that the length of laser resonant cavity was changed to adapt the changes of the fiber ring resonator which real-time tracked and locked with the external environment.Through the method of linewidth,calculated quickly that the quality value of fiber ring resonator was 107.The real-time output of the fiber ring cavity in resonant and non-resonant points frequency locked were compared and analyzed,the continuous rotation in the two kinds condition was obtained by rotation test.The detection sensitivity of fiber optic gyro system in the theory was calculated finally.The results show that the output level of the gyro value in the resonant point is 3 times than the non-resonant point,which proves the importance of the resonator fiber optic gyroscope resonant frequency locking.